PR c/77531 - __attribute__((alloc_size(1,2))) could also warn on multiplication overflow

PR c/77531 - __attribute__((alloc_size(1,2))) could also warn on multiplication overflow
PR c/78284 - warn on malloc with very large arguments

gcc/c-family/ChangeLog:

	PR c/78284
	* c.opt (-Walloc-zero, -Walloc-size-larger-than): New options.

gcc/ChangeLog:

	PR c/78284
	* builtin-attrs.def (ATTR_ALLOC_SIZE, ATTR_RETURNS_NONNULL): New
	identifier tree nodes.
	(ATTR_ALLOCA_SIZE_1_NOTHROW_LEAF_LIST): New attribute list.
	(ATTR_MALLOC_SIZE_1_NOTHROW_LIST): Same.
	(ATTR_MALLOC_SIZE_1_NOTHROW_LEAF_LIST): Same.
	(ATTR_MALLOC_SIZE_1_2_NOTHROW_LEAF_LIST): Same.
	(ATTR_ALLOC_SIZE_2_NOTHROW_LEAF_LIST): Same.
	* builtins.c (expand_builtin_alloca): Call
	maybe_warn_alloc_args_overflow.
	* builtins.def (aligned_alloc, calloc, malloc, realloc):
	Add attribute alloc_size.
	(alloca): Add attribute alloc_size and returns_nonnull.
	* calls.h (maybe_warn_alloc_args_overflow): Declare.
	* calls.c (alloc_max_size, operand_signed_p): New functions.
	(maybe_warn_alloc_args_overflow): Define.
	(initialize_argument_information): Diagnose overflow in functions
	declared with attaribute alloc_size.
	* doc/invoke.texi (Warning Options): Document -Walloc-zero and
	-Walloc-size-larger-than.

gcc/testsuite/ChangeLog:

	PR c/78284
	* gcc.dg/attr-alloc_size-3.c: New test.
	* gcc.dg/attr-alloc_size-4.c: New test.
	* gcc.dg/attr-alloc_size-5.c: New test.
	* gcc.dg/attr-alloc_size-6.c: New test.
	* gcc.dg/attr-alloc_size-7.c: New test.
	* gcc.dg/attr-alloc_size-8.c: New test.
	* gcc.dg/attr-alloc_size-9.c: New test.
	* gcc/testsuite/gcc.dg/errno-1.c: Adjust.

From-SVN: r243470

1 files changed, 15 insertions, 3 deletions

diff --git a/gcc/builtins.c b/gcc/builtins.c
index b58056c..20515e7 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -4797,12 +4797,12 @@ expand_builtin_alloca (tree exp, bool cannot_accumulate)
 {
   rtx op0;
   rtx result;
-  bool valid_arglist;
   unsigned int align;
-  bool alloca_with_align = (DECL_FUNCTION_CODE (get_callee_fndecl (exp))
+  tree fndecl = get_callee_fndecl (exp);
+  bool alloca_with_align = (DECL_FUNCTION_CODE (fndecl)
 			    == BUILT_IN_ALLOCA_WITH_ALIGN);
 
-  valid_arglist
+  bool valid_arglist
     = (alloca_with_align
        ? validate_arglist (exp, INTEGER_TYPE, INTEGER_TYPE, VOID_TYPE)
        : validate_arglist (exp, INTEGER_TYPE, VOID_TYPE));
@@ -4810,6 +4810,18 @@ expand_builtin_alloca (tree exp, bool cannot_accumulate)
   if (!valid_arglist)
     return NULL_RTX;
 
+  if ((alloca_with_align && !warn_vla_limit)
+      || (!alloca_with_align && !warn_alloca_limit))
+    {
+      /* -Walloca-larger-than and -Wvla-larger-than settings override
+	 the more general -Walloc-size-larger-than so unless either of
+	 the former options is specified check the alloca arguments for
+	 overflow.  */
+      tree args[] = { CALL_EXPR_ARG (exp, 0), NULL_TREE };
+      int idx[] = { 0, -1 };
+      maybe_warn_alloc_args_overflow (fndecl, exp, args, idx);
+    }
+
   /* Compute the argument.  */
   op0 = expand_normal (CALL_EXPR_ARG (exp, 0));